Okazaki E, Chikahisa L, Kanemaru K, Oyama Y
Laboratory of Cell Signaling (Pharmacology), Faculty of Integrated Arts and Sciences, University of Tokushima, Japan.
Jpn J Pharmacol. 1996 Aug;71(4):273-80. doi: 10.1254/jjp.71.273.
The effect of hydrogen peroxide (H2O2) on the intracellular Ca2+ concentration ([Ca2+]i) of rat thymocytes was examined by a flow cytometer and two fluorescent dyes, fluo-3-AM and ethidium bromide, a dye impermeant to intact membranes, to characterize the H2O2-induced increase in [Ca2+]i. H2O2 at concentrations greater than 30 microM dose-dependently increased the [Ca2+]i of thymocytes which were not stained with ethidium. Removal of external Ca2+ greatly reduced the degree of H2O2-induced increase in [Ca2+]i. However, H2O2 still increased the [Ca2+]i under the external Ca(2+)-free condition. Diethylmaleate, which is known to produce a chemical depletion of cellular nonprotein thiol, significantly increased the [Ca2+]i. Dithiothreitol, which is used to protect cellular nonprotein thiol, slightly decreased the [Ca2+]i, but greatly reduced the H2O2-induced increase in [Ca2+]i. Therefore, it is considered that H2O2 may increase the [Ca2+]i through a mechanism related to the effects of H2O2 on the cellular nonprotein thiol.
通过流式细胞仪以及两种荧光染料（fluo-3-AM和溴化乙锭，一种不能透过完整细胞膜的染料）来检测过氧化氢（H₂O₂）对大鼠胸腺细胞内钙离子浓度（[Ca²⁺]i）的影响，以表征H₂O₂诱导的[Ca²⁺]i升高。浓度大于30微摩尔的H₂O₂剂量依赖性地增加了未被溴化乙锭染色的胸腺细胞的[Ca²⁺]i。去除细胞外钙离子极大地降低了H₂O₂诱导的[Ca²⁺]i升高程度。然而，在无细胞外钙离子的条件下，H₂O₂仍能增加[Ca²⁺]i。已知能导致细胞非蛋白巯基化学耗竭的马来酸二乙酯显著增加了[Ca²⁺]i。用于保护细胞非蛋白巯基的二硫苏糖醇轻微降低了[Ca²⁺]i，但极大地降低了H₂O₂诱导的[Ca²⁺]i升高。因此，认为H₂O₂可能通过与H₂O₂对细胞非蛋白巯基的作用相关的机制增加[Ca²⁺]i。
